The majority decisions were due on June 1, and the dissenters set about writing a response, due on June 15. The sources say they divided up parts of the opinion, with Kennedy and Scalia doing the bulk of the writing.

The two sources say suggestions that parts of the dissent were originally Roberts' actual majority decision for the Court are inaccurate, and that the dissent was a true joint effort.

The fact that the joint dissent doesn't mention Roberts' majority was not a sign of sloppiness, the sources said, but instead was a signal the conservatives no longer wished to engage in debate with him.